Perennial ryegrass (Lolium perenne L.) (Lp) is a cool-season grass (2n=2x=14, LL) that is in wide use as turfgrass and forage grass due to superior quality and rapid establishment of plants. However, lack of drought tolerance makes Lp less persistent and reduces economical advantages of its use during hot and dry summers or dry environments.
One approach for improvement of drought tolerance in perennial ryegrass is introgression of alien genomes from other drought tolerant genera, such as fescue plants (Rie and Mondart 1985, Ames: Iowa State Univ. Press, 1985:241-246; herein incorporated by reference). Thus, plant breeders and geneticists have attempted for several decades to genetically combine perennial ryegrass (L. perenne L.) with fescue (Festuca spp.) to create novel forage grasses containing both high forage quality and good drought tolerance.
However, a major barrier in Festuca×Lolium breeding programs for providing commercial cultivars of L. perenne plants comprising the desirable traits of Festuca is the difficulty in selecting hybrids with the desired alien chromatin or chromosome addition-substitution. Further, Festuca germplasm is rapidly loss from subsequent breeding lines when attempting to retain the drought resistant Festuca germplasm and the desired agronomic traits of Lolium plants.
Therefore, despite exhaustive efforts, especially in light of the potential enormous economic and environmental significance of success, there is still a need for identification and characterization of plant genes that would confer drought tolerance to Lolium plants. Further, there remains a need for providing increased drought tolerance in L. perenne L. ryegrass plants.